Lighting Regulations in Pima County, Arizona: Preserving Dark Skies in the Desert Southwest

Introduction

Pima County, Arizona, established in 1864, stands as one of the oldest continuously inhabited areas in the United States. From prehistoric Native American settlements to the silver and gold discoveries of the mid-18th century that spurred development, this region boasts a rich cultural tapestry that continues to influence its approach to modern growth.

As the county has evolved from its original 30,000 square miles to its current 9,240 square miles, it has maintained a careful balance between development and preservation. This balance is particularly evident in the county's approach to lighting regulations, which reflect both respect for the area's historical character and recognition of environmental concerns unique to the desert Southwest.

Pima County's lighting regulations are primarily guided by the need to preserve dark skies – a natural resource particularly valued in a region home to several major astronomical observatories while also respecting the desert's natural beauty and the needs of its diverse communities.

Quick Reference Guide to Pima County Lighting Requirements

• General Code Reference: Most requirements refer to the Tucson/Pima County Outdoor Lighting Code (Title 15, Chapter 15.12)
• Required Illumination Levels:
• General seeing tasks: 5 foot-candles
• Laundry room work areas: 40 foot-candles
• Toilet room, in front of mirrors: 40 foot-candles
• Dark Sky Protection:
• Maximum correlated color temperature: 3000K
• Maximum luminous intensity: 100 nits (candela per square meter)
• Height Restrictions: Light standards for roads, parking areas and driveways shall not exceed 42 inches (with exceptions for tennis courts and horse corrals)

Indoor Lighting Requirements

Minimum Illumination Standards

The code establishes specific minimum illumination levels for various indoor spaces:

• General seeing tasks: 5 foot-candles
• Laundry room work areas: 40 foot-candles
• Toilet rooms, in front of mirrors: 40 foot-candles

Special Use Requirements

For specific commercial establishments, additional requirements apply:

• Adult amusement establishments must maintain interior illumination of not less than one candle foot measured at floor level
• Entry areas to certain establishments must be well-lighted with conspicuous signage

Swimming Pool Lighting Regulations

Safety Requirements

Pima County places significant emphasis on pool lighting for safety:

• Underwater lighting is required for hydrotherapy pools, hot tubs, and spa pools
• Pool and deck areas must be well-lighted by natural or artificial means when in use
• Electric wires shall not extend across a pool
• Underwater lighting must be designed, installed, grounded, and maintained to be safe for bathers and provide adequate illumination

Outdoor Lighting Standards

General Requirements

Throughout Pima County's code, one consistent theme emerges – most outdoor lighting must comply with the county's outdoor lighting code (Title 15):

• Security lighting sources shall not be visible from adjoining residential properties
• Lighting must be arranged to eliminate glare towards streets and adjoining properties
• Any activity producing intense glare or heat shall be performed to avoid creating a nuisance or hazard along lot lines

Height and Placement Restrictions

The county limits the height of certain lighting fixtures:

• Light standards for roads, parking lots, driveways and outdoor areas shall not exceed 42 inches in height
• Exceptions exist for tennis courts and horse corrals, though they must still comply with the outdoor lighting code

Dark Sky Protection Provisions

Purpose and Background

Pima County's dark sky protections aim to:

• Protect astronomical observation by minimizing light intrusion
• Preserve the natural environment along street frontages
• Improve the visual appearance of the community

Technical Requirements

To protect the night sky, lighting must meet these specifications:

• Maximum correlated color temperature (CCT): 3000K
• Maximum luminous intensity: 100 nits (candela per square meter)
• Externally illuminated signs must have:
• Full shielding of luminaires
• Top-down illumination only
• No light trespass onto other properties
• Sign surface must contain all light

Sign Illumination Regulations

Allowed Illumination Types

The code specifies particular sign illumination methods:

• Halo illumination
• Internal illumination where only sign characters and logos emit light

Illumination Restrictions

Several limits apply to when and how signs can be illuminated:

• Illuminated wall signs must be turned off no later than one hour after business closing
• Illuminated interior signs visible from outside cannot be lit when the business is closed
• Certain illuminated signs must be turned off by 9 PM

Prohibited Lighting Types

Some lighting features are expressly forbidden:

• Blinking, flashing, rotating and animated light sources
• Searchlights
• Signs with intermittent or varying color or intensity
• Signs that constitute a nuisance or hazard to traffic or adjacent properties

Zone-Specific Requirements

Billboard Regulations

Illumination rules vary by zone:

• No illumination permitted for billboards in CB-2, CI-1, CI-2, and CI-3 zones
• Billboards with wooden support structures replaced with metal support structures cannot be illuminated

Residential Properties

Residential properties have specific limitations:

• No illumination allowed for single-family residential property signs
• No light trespass permitted onto adjoining residential properties

Supporting Pima County's Lighting Vision

At Bock Lighting, we understand and appreciate Pima County's commitment to preserving its dark skies while ensuring functional and safe lighting for residents and businesses. Our Northeast Ohio manufacturing heritage, dating back to 1918, has given us a deep appreciation for communities that balance modern needs with historical and environmental preservation.

We recognize that Pima County's regulations reflect the region's unique character – from its astronomical observatories to its desert landscapes and rich cultural history. Our team stays informed about local lighting requirements throughout the country, making us a valuable educational resource for those navigating these regulations.

Bock Lighting shares Pima County's dedication to sustainable lighting practices that minimize light pollution while providing appropriate illumination for safety and functionality. We believe that thoughtful lighting design can enhance community character rather than detract from it.

As lighting technology continues to evolve, we remain committed to helping communities like Pima County achieve their vision for responsible outdoor lighting that respects both their heritage and their natural environment.

Conclusion

Pima County's lighting regulations reflect its unique position as a region with both rich historical heritage and significant astronomical resources. The careful balance between providing adequate lighting for safety and functionality while protecting dark skies demonstrates the county's commitment to responsible development.

Property owners should familiarize themselves with the Tucson/Pima County Outdoor Lighting Code (Title 15, Chapter 15.12) for comprehensive guidelines, as most specific regulations throughout the county code refer back to this document. By adhering to these standards, residents and businesses contribute to preserving one of the region's most valuable natural resources – its dark, star-filled skies.

Navigating lighting regulations can be complex, but understanding the purpose behind these requirements helps clarify their importance to Pima County's identity and future. As the county continues to grow, these regulations will help ensure that development occurs in harmony with the natural environment that makes this region so special.